Protein kinase inhibitor

ABSTRACT

Disclosed herein are compounds of the formula I                    
     wherein A and C are independently H, alkyl of 1-6 carbon atoms, hydroxy, or alkoxy of 1-6 carbon atoms; 
     B is hydroxy or alkoxy of 1-6 carbon atoms; and 
     Y is cyano,                    
      —C(NR 1  R 2 )═C(CN) 2 ; 
     wherein X═O or S, and R 1  and R 2  are independently 
      H, benzyl, —CH(CH 3 )C 6 H 6 , 
      —(CH 2 ) n C 6 H 6 , phenyl; —CO 2 R; 
      n=2-4; R is lower alkyl of 1-6 carbon atoms which are useful for treating inflammation and immunological diseases.

This application is a continuation (and claims the benefit of priorityunder 35 USC 120) of U.S. application Ser. No. 08/825,662, filed Apr. 3,1997, now U.S. Pat. No. 5,854,285, issued Dec. 29, 1998.

FIELD OF THE INVENTION

The present invention relates to the method of use of styrenederivatives to treat inflammation and immunological diseases.

BACKGROUND OF THE INVENTION

The present invention is based on the crucial role played by signalingpathways in affecting the function of cytokines. Cytokines are moleculessecreted by immune cells and are important in mediating immuneresponses. Cytokines effect their functions at the site of secretion orat distant sites. Cytokines initiate their responses by binding to theirrespective receptors. This receptor-ligand interaction induces a signaland leads to the transcription of new genes that change the functionalcapacity of the target cell. Thus the effect of cytokines may result inthe secretion of other cytokines, altered cellular function, celldivision or differentiation. In most immune cells (T, B and macrophages)cytokine receptors themselves act as protein tyrosine kinases that arephosphorylated upon ligation of the receptor or are closely linked tophosphotyrosine kinases (PTK's).

Inhibitors of PTK function are known, such as querestin, the first onewhich was isolated. Querestin was found to inhibit not only PTK's butother enzymes such as cAMP dependent kinase, protein kinase C (PKC) andATP requiring enzymes. Other naturally occurring compounds such aserbastatin, herbamycin and levandestin affect predominantly the functionof PTK's and have been termed tyrphostins. Most tyrphostins are 100-1000fold more potent in inhibiting PTK's than PKA, PKC or other calciumdependent kinases. So far the role of tyrphostins has focused on theirpotential application in neoplastic diseases. A recent therapeutic testof tyrphostins has been in the treatment of acute lymphoblasticleukemia, in which a known JAK2 kinase inhibitor was shown to inhibitthe proliferation of leukemic cells without affecting mitogen-induced Tcell proliferation.

The present invention is directed to treatment of immunological diseasesor inflammation. The principal elements of the immune system aremacrophages or antigen-presenting cells, T cells and B cells. The roleof other immune cells such as NK cells, basophils, mast cells anddendritic cells are known, but their role in primary immunologicdisorders is uncertain. Macrophages are important mediators of bothinflammation and providing the necessary “help” for T cell stimulationand proliferation. Most importantly macrophages make IL 1, IL 12 andTNFα all of which are potent pro-inflammatory molecules and also providehelp for T cells. In addition, activation of macrophages results in theinduction of enzymes, such as cyclooxygenase II (COX II), nitric oxide(NO) and other free radicals capable of damaging normal cells. Manyfactors activate macrophages, including bacterial products,superantigens and interferon gamma (IFNγ). It is believed that PTK's andother undefined cellular kinases are involved in the activation process.

Macrophages take up and break down antigens into small fragments. Thesefragments then associated with the major histocompatibility complex II(MHC II). This complex of antigen fragments and MHC II is recognized bythe T cell receptor. In association with appropriate co-stimulatorysignals this receptor-ligand interaction leads to the activation andproliferation of T cells. Depending on the route of administration ofantigen, their dose and the conditions under which macrophages areactivated, the immune response can result in either B cell help andantibody production or on the development of cell mediated response.Since macrophages are sentinel to the development of an immune response,agents that modify their function specifically their cytokine secretionprofile are likely to determine the direction and potency of the immuneresponse.

SUMMARY OF THE INVENTION

This invention is directed to a method of treating immunologicaldiseases or inflammation with compounds of formula I shown below. Thecompounds inhibit the secretion of pro-inflammatory cytokines and thusprevent the deveelopment or inhibit established inflammatory responses.

Wherein A and C are independently H, alkyl of 1-6 carbon atoms, hydroxy,or alkoxy of 1-6 carbon atoms;

B is hydroxy or alkoxy of 1-6 carbon atoms; and

Y is cyano,

 or

—C(NR₁R₂)═C(CN)₂;

 wherein X═O or S, and R₁ and R₂ are independently

H, benzyl, —CH(CH₃)C₆H₅,

—(CH₂)_(n)C₆H₅, phenyl; —CO₂R;

n=2-4; R is lower alkyl of 1-6 carbon atoms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show the IL-12 and nitric oxide inhibition of tyrphostin1A described in Example 1.

FIGS. 2A, 2B and 2C show the TNFα production by tyrphostin 1A in threemacrophage cell populations.

FIG. 3 shows the prevention of EAE in mice by tyrphostin 1A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As used herein the term tyrphostins is intended to denote a family oforganic molecules that have the effect of inhibiting protein tyrosinekinases.

The immune diseases include those mediated by signaling pathways linkedto pro-inflammatory cytokines, such as, multiple sclerosis, rheumatoidarthritis, contact and a topic dermatitis.

The compounds used in accordance with the present invention are those ofthe formula I. The alkyl and alkoxy groups in formula I may be linear orbranched. A preferred class of compounds is that in which A and C areindependently hydrogen or hydroxy and Y is cyano. A particularlypreferred compound within this class is the compound in which B ismethoxy and A and C are both hydrogen.

The compounds of the formula I are obtained by synthetic methods knownin the art. See Gazit et al., J. Med. Chem., 1991, 34:1896-1907; 1989,32:2344-2352; 1993, 36:3556-3564; and U.S. Pat. No. 5,217,999, issuedJun. 8, 1993 to Levitski et al., all of which are incorporated byreference herein in their entirety.

The compounds may be administered to the host suffering frominflammation or a immunological disease using any convenientadministration technique, where such techniques include intravenous,intradermal, intramuscular, subcutaneous, oral, and the like. The dosagedelivered to the host will necessarily depend on the route by which theactive compound is administered, but will generally range from about 1to 500 mg/70 kg human body weight/day.

The compounds of this invention may be used in formulations usingacceptable pharmaceutical vehicles for enteral, or parenteral,administration, such as, for example, water, alcohol, gelatin, gumarable, lactose, amylase, magnesium stearate, talc, vegetable oils,polyalkylene glycol, and the like. The compounds can be formulated insolid form, e.g., as tablets, capsules, dragees and suppositories, or inthe liquid form, e.g., solutions, suspensions and emulsions. Thepreparations may also be delivered transdermally or by topicalapplication.

The following examples are presented by way of illustration, and are notintended to limit the invention in any way.

EXAMPLE 1

Tyrphostin A1 (Formula I: A and C are H, B is methoxy, Y is CN) is asefficient as A10 (A is H, B is —NO₂, C is OH, Y is —CN) and B42 (A and Bare OH, C is H, Y is C(O)NHCH₂C₆H₆) in inhibiting nitric oxide and IL 12Secretion by splenic macrophages.

Tyrphostin A1 has been used as a negative control for tyrphostinsbecause of it weak effect on inhibition of epidermal growth factorreceptor (EGFR) kinase activity. Tyrphostin A10 has been shown to beprotective in septic shock and B42 is effective in preventing the growthof leukemic cells in acute lymphoblastic leukemia.

The effects of these three tyrphostins on the secretion ofpro-inflammatory cytokines from macrophages were compared. Mouse splenicmacrophages were stimulated with 5 ugh/ml lipopolysaccharide (LPS) andtreated with varying doses of tyrphostins. The cells were cultured for72 hr and the amount of IL 12 and nitric oxide was measured. TyrphostinsA1, A10 and B42 all inhibited IL 12 production. In general, tyrphostinA1 was more potent (FIG. 1A) than the other tyrphostins in inhibiting IL12 secretion. Similar results were obtained with respect to nitric oxidelevels, with tyrphostin A1 (FIG. 1B) showing good results.

The effect of tyrphostin A1 on inhibition of TNFα was examined in vitroin a cultured macrophage cell line, peritoneal macrophages and splenicmacrophages. Cells were cultured with 5 ug/ml LPS in the presence ofvarying concentrations of tyrphostin A1. Following 24 hr incubation,cell supernatants were harvested and the amount of TNFα was measuredusing a biological assay. Tyrphostin A1 inhibits TNFα secretion in threedifferent populations (ANA-1, FIG. 2A; peritoneal macrophage cells, FIG.2B; splenic macrophages cells, FIG. 2C) of macrophages. FIGS. 2A and 2Cshow that the inhibition occurs in a dose dependent fashion.

Tyrphostin A1 was also tested for its ability to modulate the functionof cyclooxygenase (COX II), an enzyme found in cells in inflammatorylesions. Hence, down regulation of this enzyme will be highly beneficialin damping inflammation. The induction of COX II in murine peritonealmacrophages activated with LPS was inhibited by tyrphostin A1.

The restrictive effects of tyrphostin A1 on pro-inflammatory cytokineswas confirmed by examining the enhanced expression of class II MHCmolecules induced by IFNγ. Tyrphostin A1 at concentrations at which itinhibits secretion of pro-inflammatory cytokines had no effect onenhancement of class II MHC levels by IFNγ (Table I).

TABLE I % MHC Class II + Stimulation Cells None 26.6% IFNγ 58.2 IFNγ +Tyrphostin Al (1 μM) 64.1% IFNγ + Tyrphostin Al (10 μM) 60.4%

The selectivity of tyrphostins for macrophages was further confirmed bytesting their effects on T cell proliferation induced by either IL 12 orIL 2. Mitogen stimulated mouse splenic T cells were cultured in serumfree medium for 24 hr. The cells were then stimulated with either 1 U/mlIL 2 or 10 U/ml IL 12 in the presence or absence of tyrphostin A1.Tyrphostin B42 inhibited T cell proliferation when cultured with IL 2 orIL 12. Tyrphostin A1 and A10 did not show any significant inhibition.

EXAMPLE 2

Tyrphostin A1 is tested on experimental allergic encephalomyelitis (EAE)in mice.

The condition EAE is an animal model which mimics human multiplesclerosis. Therefore, the clinical efficacy of tyrphostin A1 was testedin mice suffering from EAE. Female SJL/J mice were randomly assignedinto 2 groups of 5 animals each. EAE was induced by subcutaneousimmunization with mouse spinal cord homogenate (800 ug/animal) incomplete Freund's adjuvant on days 0 and 7. One group of animals wastreated with 5 mg/kg tyrphostin A1 subcutaneously on days 1, 3, 5, 7 and9 after immunization. Animals were observed and graded for the clinicalsigns every day. The severity of the disease was scored as: 1, loss oftail tone; 2′ hind limb weakness; 3, hind limb paralysis; 4, moribundand 5, death.

FIG. 3 shows the summary of data on subcutaneous administration oftyrphostin A1 indicating a decrease in the clinical severity of EAE.Animals in the control group had a peak mean severity of 2.5 at day 20.This was reduced to 1.25 at day 20 by tyrphostin A1.

The data demonstrate the utility of tyrphostin A1 in blockingpro-inflammatory cytokines and in treating a prototype inflammatorydisease.

What is claimed is:
 1. A method for treating inflammation in a patientsuffering from an inflammatory condition comprising the step ofadministering a therapeutically effective amount of a compound of theformula:

wherein A and C are independently H, alkyl of 1-6 carbon atoms, hydroxy,or alkoxy of 1-6 carbon atoms provided that either A or C, but not both,may be H; B is hydroxy or alkoxy of 1-6 carbon atoms; and Y is

 wherein X═O or S, and R₁ and R₂ are independently benzyl, —CH(CH₃)C₆H₅,—(CH₂)_(n)C₆H₅, phenyl; —CO₂R; n=2-4; R is lower alkyl of 1-6 carbonatoms.
 2. A method according to claim 1 wherein A and B are hydroxy, Cis hydrogen and Y is —C(O)NHCH₂C₆H₆.
 3. The method of claim 1 whereinsaid compound is administered in a dose range from 1 mg/day to 500mg/day.
 4. The method of claim 1 wherein said compound is administeredorally, parenterally, transdermally or topically.
 5. A method fortreating an immunological disease in a patient afflicted with saiddisease comprising the step step of administering a therapeuticallyeffective amount of a compound of the formula:

wherein A and C are independently H, alkyl of 1-6 carbon atoms, hydroxy,or alkoxy of 1-6 carbon atoms provided that either A or C, but not both,may be H; B is hydroxy or alkoxy of 1-6 carbon atoms; and Y is

 wherein X═O or S, and R₁ and R₂ are independently benzyl, —CH(CH₃)C₆H₅,—(CH₂)_(n)C₆H₅, phenyl; —Co₂R; R is lower alkyl of 1-6 carbon atoms. 6.The method according to claim 5 wherein said disease is multiplesclerosis.